White-box testing is a method of testing software that tests internal structures or workings of an application, as opposed to its functionality (i.e. black-box testing). In white-box testing an internal perspective of the system, as well as programming skills, are required and used to design test cases. The tester chooses inputs to exercise paths through the code and determine the appropriate outputs. This is analogous to testing nodes in a circuit, e.g. in-circuit test

In-circuit test

In-circuit test is an example of white box testing where an electrical probe tests a populated printed circuit board , checking for shorts, opens, resistance, capacitance, and other basic quantities which will show whether the assembly was correctly fabricated...

ing (ICT).

While white-box testing can be applied at the unit, integration

Integration testing

Integration testing is the phase in software testing in which individual software modules are combined and tested as a group. It occurs after unit testing and before validation testing...

 and system

System testing

System testing of software or hardware is testing conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements. System testing falls within the scope of black box testing, and as such, should require no knowledge of the inner design of the code or...

 levels of the software testing

Software testing

Software testing is an investigation conducted to provide stakeholders with information about the quality of the product or service under test. Software testing can also provide an objective, independent view of the software to allow the business to appreciate and understand the risks of software...

 process, it is usually done at the unit level. It can test paths within a unit, paths between units during integration, and between subsystems during a system level test. Though this method of test design can uncover many errors or problems, it might not detect unimplemented parts of the specification or missing requirements.

White-box test design techniques include:

• Control flow
  Control flow
  In computer science, control flow refers to the order in which the individual statements, instructions, or function calls of an imperative or a declarative program are executed or evaluated....
  
   testing
• Data flow testing
• Branch testing
• Path testing

Hacking

In penetration test

Penetration test

A penetration test, occasionally pentest, is a method of evaluating the security of a computer system or network by simulating an attack from malicious outsiders and malicious insiders...

ing, white-box testing refers to a methodology where a white hat hacker has full knowledge of the system being attacked. The goal of a white-box penetration test is to simulate a malicious insider who has some knowledge and possibly basic credentials to the target system.

See also

• Black-box testing
• Grey box testing
• Metasploit Project
  Metasploit Project
  The Metasploit Project is an open-source computer security project which provides information about security vulnerabilities and aids in penetration testing and IDS signature development....
  
  

External links

• BCS SIGIST (British Computer Society Specialist Interest Group in Software Testing): Standard for Software Component Testing, Working Draft 3.4, 27. April 2001.
• http://agile.csc.ncsu.edu/SEMaterials/WhiteBox.pdf has more information on control flow testing and data flow testing.
• http://research.microsoft.com/en-us/projects/pex/ Pex - Automated white-box testing for .NET